A preform is a formation of raw material that can be used to produce and manufacture a final part. In some instances, a preform may be formed by combining a number of smaller blocks of raw material to form a larger structure. The larger structure may have a shape that is close to a final shape of the part, such that the structure can be machined to produce a final part.
Joining technologies such as mechanical fastening or friction welding may be used to manufacture a preform. By way of example, with linear friction welding (LFW), one part is oscillated laterally in a linear reciprocating motion while pressed against another stationary part. The resulting friction heats the parts, and after a period of time, the two parts are brought into alignment and forged together.
In the past, engineers manufactured parts by starting with a solid block and then machining the block down to form a final part. The process of manufacturing a part from a preform allows complex shapes to be manufactured while saving raw material costs and manufacturing time. For instance, machining a final part from a preform wastes less excess material and less milling cutters and may therefore be more cost-effective than machining a part from a solid block. In addition, machining a final part from a preform may be faster than machining a final part form a solid block.
Today, engineers manually design preforms by looking at the geometry of a final part, and deciding how and where to divide the final part into a number of blocks that can be joined together to form a preform. After deciding on a desired division of the part into blocks, an engineer then analyzes the feasibility of fabricating a preform from the resulting blocks. It may, for instance, be impracticable or impossible to join some of the blocks in the manner contemplated by the engineer due to limitations of a joining technology. As an example, it may be impossible to join two blocks using LFW if the welding surface area between the two blocks exceeds a welding surface area threshold. Similarly, even if it is possible to join a first block to a second block, it may be impossible to then join the combination of the first and second blocks to a third block using LFW. Thus, evaluating the feasibility of fabricating a preform using LFW may involve calculating the welding surface areas of multiple welds.
Further, after deciding on a desired division of the part into blocks, the engineer may analyze the amount of raw material required to create the preform. For instance, the engineer may determine the dimensions of each of the blocks, and calculate the total volume of the preform based on the dimensions.
To design a preform that is easier to assemble or requires less raw material, the engineer may revise the division of the final part, and then reanalyze the feasibility of fabricating the preform and the required amount of raw material. The entire process of designing, analyzing, and revising a preform can take a number of hours, and may be especially time-intensive when dealing with parts having complex shapes. Improvements are therefore desired.